Controlled release buccal patches were fabricated using Eudragit NE40D and
studied. Various bioadhesive polymers, namely hydroxypropylmethyl cellulose
, sodium carboxymethyl cellulose and Carbopol of different grades, were inc
orporated into the patches, to modify their bioadhesive properties as well
as the rate of drug release, using metoprolol tartrate as the model drug. T
he in-vitro drug release was determined using the USP 23 dissolution test a
pparatus 5 with slight modification, while the bioadhesive properties were
evaluated using texture analyzer equipment with chicken pouch as the model
tissue. The incorporation of hydrophilic polymers was found to affect the d
rug release as well as enhance the bioadhesiveness. Although high viscosity
polymers can enhance the bioadhesiveness of the patches, they also tend to
cause non-homogeneous distribution of the polymers and drug, resulting in
non-predictable drug-release rates. Of the various bioadhesive polymers stu
died, Cekol 700 appeared to be most satisfactory in terms of modifying the
drug release and enhancement of the bioadhesive properties. (C) 1999 Elsevi
er Science B.V. All rights reserved.